Boss wants to “fine” employees who don’t swipe their ID at the gate and wait for it to close before driving in, can he do this?

I work for a delivery company in New Hampshire that rhymes with “WedEx Excess;” in order to enter our facility we must scan our ID’s and then drive through a gate. The gate takes about a minute to open and then a minute to close, and management is pissed that employees are simply going in behind the employee who swipes in first, as opposed to waiting 60 seconds for the gate to close and then swiping in again. They say it’s a “security risk” and have said that anyone who doesn’t wait for the gate to close and then swipe in will be fined an undisclosed amount. Is this even legal? I wanted to speak up but I was afraid